Skip to main content

Full text of "Handling and shipping strawberries without refrigeration"

See other formats


Historic, archived document 

Do not assume content reflects current 
scientific knowledge, policies, or practices 





CIRCULAR No. 515 FEBRUARY 1939 \\J| 

UNITED STATES DEPARTMENT OF AGRICULTURE 
WASHINGTON, D. C. 



HANDLING AND SHIPPING STRAWBERRIES WITHOUT 

REFRIGERATION 

By D. F. Fisher, principal horticulturist, and J. M. Lutz, assistant physiologist, 
Division of Fruit and Vegetable Crops and Diseases, Bureau of Plant Industry x 



CONTENTS 



Page 

Introduction 1 

Material and methods 1 

Investigations on harvesting 2 

Effect of temperature at time of harvest. . 2 

Effect of care in harvesting 3 

Effect of maturity on shipping quality 4 

Rate of ripening of strawberries and its 

influence on frequency of harvesting 5 



Page 

Investigations on packing 6 

Effect of type of crate 6 

Effect of packing in the shed 9 

Comparison of faced and jumble packs.. . 13 

Effect of cellophane caps 14 

Effect of temperature on decay 15 

Summary 15 



INTRODUCTION 

Motortrucks are being relied upon more and more for the trans- 
portation of strawberries from producing districts to markets that 
can be reached within 24 to 36 hours by this means. The Bureau of 
Agricultural Economics estimated that in the years 1933 and 1934, 
53 percent of all strawberry shipments in the United States moved 
by this method. 

Strawberries moved by truck are seldom refrigerated and often are 
exposed to very warm temperatures in transit. The use of precooling 
to control decay and maintain the fruit in good marketable condition 
during shipment in refrigerator cars as described by Rose and Gor- 
man 2 obviously does not apply to truck shipments. 

The purpose of the experiments here reported was to study har- 
vesting, handling and packing methods, and other practices used with 
strawberries to determine how the loss in keeping quality, because of 
adverse temperatures in nonrefrigerated shipments, could be kept to 
the minimum. 

MATERIAL AND METHODS 

The strawberries used in these investigations were grown at Belts- 
ville and Salisbury, Md., in 1934 and 1935, and at Willard, N. C, in 
1935 and 1936. 

The fruit from North Carolina was shipped by express or motor- 
truck to Washington, D. C, where it was inspected either the day of 
its arrival (1 day after harvesting) or the following day, or both. 
When time and fruit permitted, two inspections were made of each 

1 The writers wish to acknowledge their appreciation to Charles Dearing. superintendent of the Coastal 
Plain Experiment Station, Willard, N. C, and George M. Darrow, of the Division of Fruit and Vege- 
table Crops and Diseases, for furnishing facilities for some of this work; and to Dean H. Rose, R. C. Wright, 
and CO. Bratley, who assisted with the inspections. 

2 Rose, Dean H., and Gorman, E. A., Jr. handling, precooling, and transportation of Florida 
strawberries. U. S. Dept. Agr. Tech. Bull. 525, 58 pp., illus. 1936. 

103974° — 39 1 



IT. S. DEPARTMENT OF AGRICULTURE 

lot of fruit. The results of inspections made 1 day after harvesting- 
are applicable to nonrefrigerated truck shipments from the vicinity 
of Wilmington, N. C, to points as far north as Baltimore, Md., or to 
similar shipments from Delaware and the Eastern Shore of Maryland 
and Virginia to New York City. The results of inspection on the 
following day are similarly applicable to shipments from North Caro- 
lina to New York City. The fruit obtained in Maryland was trucked 
to Washington, D. C, where it was inspected 1 or 2 days after har- 
vesting. One test by nonrefrigerated express was made from Belts- 
ville, Md., to New York City, the berries being inspected the day 
after harvesting. 

In each test all lots were comparable at time of shipment. After 
arrival at market destination the percentage of sound, decayed, 3 and 
bruised berries was determined. Unless otherwise stated, all figures 
relative to shipping quality are in percentage by weight, although the 
percentages were generally recorded both by weight and by number. 
However, the former expression is the most significant commercially, 
since it indicates the actual quantity of fruit falling into the various 
classifications regardless of size. When data are presented in per- 
centages by number, those of sound fruit are slightly higher than when 
expressed in percentage by weight, because larger berries are more 
subject to bruising and decay. 

The air temperature to which the fruit from North Carolina was 
subjected after shipment was approximately 60° F., whereas the hold- 
ing temperature for the berries from Maryland was usually between 
70° and 80°. 

Some of the fruit harvested at Beltsville, and trucked only about 
15 miles, was jolted for 8 hours on an apparatus designed to simulate 
longer transit conditions. 4 

The weather conditions in North Carolina in 1935 during the period 
when these experiments were conducted were especially conducive to 
the development of decay. A heavy rain fell on April 28 and was 
followed by rather warm weather during the week the test lots w T ere 
shipped. Likewise, the fruit obtained from Beltsville, was generally 
poor in keeping quality because as a rule it was too ripe for distant 
shipment, there being a rather high percentage of full-ripe berries. 
The fruit obtained in North Carolina was more satisfactory in this 
regard, being about the same as usual in commercial shipments, with 
berries ranging from half ripe to full ripe. 

INVESTIGATIONS ON HARVESTING 
EFFECT OF TEMPERATURE AT TIME OF HARVEST 

Stevens and Wilcox, 5 working at Hammond, La., in 1917, concluded 
that when shipment is made under refrigeration, berries picked in the 
early morning are cool and less likely to decay than those picked 
during the heat of the day. In this study the same conclusion was 
reached when strawberries were shipped without refrigeration. The 

3 In making these inspections no attempt was made to determine separate percentages for different kinds 
of rots. 

* Rose, DeanH., and Lutz, J. M. bruising and freezing of apples in stokage and transit. U.S. 
Dept. Aer. Tech. Bull. 370, 15 pp., illus. 1933. 

s Stevens, Neil E., and Wilcox, R. B. further studies of the rots of strawberry fruits. U. S. 
Dept. Agr. Bull. 686, 14 pp. 1918. See p. 12. 



HANDLING AND SHIPPING STRAWBERRIES 6 

results obtained, as presented in table 1, indicate the desirability of 
harvesting strawberries as early as possible in the morning while the 
temperature is relatively cool. It is interesting to note that the per- 
centage of soft-bruised berries was rather closely correlated with 
the temperature at the time of picking. Apparently, picking the 
berries when they were warm was conducive to this type of injury. 

Table 1. — Influence of temperature at time of harvest on shipping quality of Blake- 
more strawberries; inspected 2 days after harvesting 

[Shipped by nonrefrigerated express from Wallace, N. C, to Washington, D. C] 



Date of picking 



Time of picking 



Temperature at 
time of harvest 



Fruit 



Sound 



Soft 
bruised 



Decayed 



Apr. 30, 1935 

May 2, 1935. 
May 6, 1936, 



6 a. m 

9 a. m 

12 m 

3 p. m 

16 a. m. 1 .. 
9 a. m 
12 m 
3 p. m 

[7:30 a.m. 
<M1:30 a. m 
1.2:30 p. m. 



Percent 
63.5 
36.9 
42.8 
28.1 
69.4 
53.4 
34.7 
71.7 
69.5 
66.6 
61.0 



Percent 
17.5 
27.1 
46.2 
54.6 
12.9 
33.0 
47.8 
24.1 
11.6 
18.6 
22.4 



Percent 
19.0 
36.0 
11.0 
17.3 
17.7 
13.6 
17.5 
4.2 
18.9 
14.8 
16.6 



i Dew present. 



EFFECT OF CARE IN HARVESTING 



The results given in tables 2 and 3 on the effect of care in harvesting- 
are self-explanatory. It can be readily seen that care to avoid injury 
in picking and handling at time of harvest resulted in better carrying 
quality. The results obtained with the fruit from North Carolina 
(table 2) illustrate the importance of having adequate supervision by 
a foreman who will insist upon careful picking and handling of the 
fruit. Much of the loss due to careless handling comes from infection 
by Rhizopus. It is important to note, therefore, that Stevens 6 
reports "Rhizopus sp. does not readily penetrate the unbroken 
epidermis from the outside." See also Stevens and Wilcox 7 on this 
subject. 

Table 2. — Shipping quality of Blakemore strawberries as influenced by care in 
harvesting; inspected 2 days after harvesting 



[Shipped by express from Wallace, N. C, to Washington, D. C] 



Date of picking 



Apr. 30, 1935. 
May 2, 1935.. 



Care in harvesting 



/Careful. 
\ Careless 
fCareful. 
\Careless 



Sound 



Percent 
63.5 
40.7 
71.7 
26.4 



Soft 
bruised 



Percent 
17.5 
21.2 
24.1 
36.2 



Decayed 



Percent 

19.0 

38.1 

4.2 

37.4 



8 Stevens, Neil E., pathological histology of strawberries affected by species of botrytis 
and rhizopus. Jour. Agr. Research 6: 361-366, illus. 1916. 

7 Stevens, Neil E., and Wilcox, R. B. rhizopus rot of strawberries in transit. U. S. Dept. Agr. 
Bull. 531, 22 pp., illus. 1917. 



4 



CIRCULAR 515, U. S. DEPARTMENT OF AGRICULTURE 



Table 3. — Shipping quality of three varieties of strawberries grown at Beltsville, 
Md., as influenced by care in harvesting ; percentage of sound and of soft bruised 
strawberries 24 hours after picking and after holding in open air at 70° to 80° F. 

[Jolted for 8 hours after harvesting] 





Dorsett 


Blakemore 


Fairfax 


Method of harvesting 


Sound 


Soft 
bruised 


Sound 


Soft 
bruised 


Sound 


Soft 
bruised 


Careful . _ _ _ 


Percent 
78.3 
64.7 


Percent 
18.3 
35.3 


Percent 
88.0 
84.8 


Percent 
6.3 
11.5 


Percent 
100.0 
84.2 


Percent 





15.8 







EFFECT OF MATURITY ON SHIPPING QUALITY 

The effect of maturity at harvest on the shipping quality of straw- 
berries was studied, and the results are presented in tables 4 and 5. The 
term "half ripe" refers to berries showing 25 to 50 percent of the sur- 
face white and the remainder pink; "full ripe" is considered full eating 
ripe but not overripe; "nearly ripe" represents a stage of maturity 
intermediate between the other two. 



Table 4. — Relation of maturity to shipping quality; inspected 2 days after harvesting 
[Shipped without refrigeration from Wallace, N. C, to Washington, D. C] 



Date of pick- 
ing 



Apr. 29, 19351 



May 3, 1935.. 



_ May 5, 1936. 



Method of 
shipping 



Express 



Truck 



Express 



Maturity at harvest 



Full ripe 

Nearly ripe 

Half ripe (25 to 50 percent 

white). 
Full ripe 



Nearly ripe. 



Half ripe (25 to 50 percent 
white) . 



Full ripe 

Commercial (half to full 

ripe— mostly full ripe). 

Half ripe 



Sound 


Soft 
bruised 


De- 
cayed 


Percent 
25.6 
46.2 
52.3 


Percent 
41.9 
32.8 
33.3 


Percent 
32.5 
21.0 

14.4 


66.7 


( 2 ) 


33.3 


84.6 


( 2 ) 


15.4 


93.7 


( 2 ) 


6.3 


13.2 
40.9 


66.4 
49.8 


20.4 
9.3 


53.1 


38.6 


8.3 



Color and flavor 
when inspected 



A few berries over- 
ripe. 

Good-eating ripe; full 
color. 

Nearly full color but 
not quite full fla- 
vor. 



1 Calculated as percent by number on Apr. 29, 1935. 

2 Very few soft bruises were present in this shipment, and they are included under "decayed." 

Table 5. — Relation of maturity to shipping quality; harvested at Beltsville, Md., 

June 10, 1935 

[Jolted 8 hours] 





Maturity at harvest 


Inspected June 11 


Inspected June 12 


Variety 


Sound 


Soft 
bruised 


Decayed 


Sound 


Soft 
bruised 


Decayed 




[Full ripe. . 


Percent 
13.5 
73.3 
62.9 
93.4 


Percent 

46.5 

14.7 

22.8 

3.0 


Percent 

40.0 

12.0 

14.3 

3.6 


Percent 
7.0 
40.6 
40.7 
73.6 
88.9 
30.4 
63.8 
82.5 


Percent 
24.2 

3.5 
26.4 

2.4 

5.3 
28.8 
22.1 

3.7 


Percent 
68.8 




(.Nearly ripe . 


55.9 






[Full ripe . . . 


32.9 


Fairfax.. . . 




24.0 




[Half ripe 


5.8 


Dorsett 


[Full ripe 


42.9 
75.4 


38.8 
17.8 


18.3 
6.8 


40.8 
14.1 




(.Half ripe 


13.8 















HANDLING AND SHIPPING STKAWBERRIES 5 

Berries that were fully ripe when shipped carried very poorly in 
the absence of refrigeration. Considerable improvement in carrying 
quality was noted in berries picked nearly ripe, and still further im- 
provement in those at the half -ripe stage. As shown in table 5, there 
were fewer sound berries 1 day after harvesting in the fruit picked 
when fully ripe than there were 2 days after harvesting in the fruit 
picked nearly ripe. Although fruit picked when half ripe had the best 
carrying quality, it did not develop full flavor and probably had not 
developed to full size in the field, although no measurements were 
made of increase in size during ripening on the plant. When berries 
are shipped without refrigeration to markets that cannot be reached 
within 24 hours after harvesting, the full-ripe stage is too ripe and the 
nearly ripe stage is more desirable. When it is necessary to hold the 
fruit at warm temperatures for a period of 2 days, the half-ripe to 
nearly ripe stage would be preferable, although as indicated in table 4, 
this would necessarily be at the sacrifice of color and eating quality. 
As shown in table 6, berries of three leading commercial varieties 
picked when fully ripe and held without refrigeration were mostly 
overripe in 2 days. Those picked when half ripe were not quite in 
prime condition for eating in 2 days, and those picked when nearly 
ripe were mostly full ripe the following day and were not generally 
overripe on the second day. 



Table 6. — Influence of maturity at harvest on degree of ripeness after 1 and 

at room temperature 

[Harvested at Beltsville, Md., June 10, 1935] 



days 



Variety 


Maturity at har- 
vest 


Inspected June 11 


Inspected June 12 




[Full ripe _ 


Full ripe; few overripe . - - . 


Mostly overripe. 


Blakemore 


<Nearly ripe 

[Full ripe - _ 


Nearly ripe to full ripe; mostly full 

ripe. 

Mostly full ripe; a few overripe 

Nearly ripe to full ripe; mostly full 

ripe. 


Full ripe. 
Mostly overripe. 




1 Nearly ripe 

[Half ripe . 


Full ripe; few overripe. 




Nearly ripe to full ripe. 




[Full ripe 




Mostly overripe. 




■(Nearly ripe 




Full ripe. 








Nearly ripe. 











RATE OF RIPENING OF STRAWBERRIES AND ITS INFLUENCE ON FREQUENCY OF 

HARVESTING 

In order to determine the rate of ripening, a number of strawberries 
at each of the three stages of maturity were tagged on the plant at 
various times during the 1935 season, and the daily amount of ripen- 
ing was recorded. The results obtained in North Carolina are shown 
below. 

Average time from- — Days 

Half ripe to nearly ripe 1^2 

Nearly ripe to full ripe 1/12 

Full ripe to overripe 1/1* 

Half ripe to overripe 5 

Nearly ripe to overripe 3^j 

Half ripe to full ripe 3^ 

The average temperature during this test was rather high, so that 
ripening probably proceeded somewhat more rapidly than^ usual, 
although conditions similar to these are to be expected during the 



6 CIIICULAE 515, U. S. DEPARTMENT OF AGRICULTURE 

strawberry-harvesting season. No detailed temperature records were 
kept in the field during this test, but those obtained at the Wilmington, 
N. C, weather station (about 40 miles away) show a maximum of 
88° F. and a minimum of 53° during this period. The average 
temperature was 72° (average of daily maxima and minima). 

The data given on page 5 emphasize the importance of picking the 
plants clean of all berries of a suitable stage of ripeness. If straw- 
berries are picked every other day when fully ripe, fruit that is missed 
would be overripe at the next picking under conditions similar to 
those prevailing during this experiment, and nearly ripe berries that 
are missed would be full ripe and of poor shipping quality at the next 
picking (table 4). If berries are picked every third day, both nearly 
ripe and full ripe berries that were not taken at one picking would 
probably be overripe at the subsequent picking, and if berries desig- 
nated as half ripe in this report were not removed at one picking, they 
would probably be full ripe at the next picking and consequently of 
poor carrying quality. 

Kesults on several varieties of strawberries similarly obtained at 
Beltsville are given in table 7. The average temperature during this 
period was 67° F., the minimum being 48° and the maximum 84°. 



Table 7. — Rate of ripening of strawberries of five varieties at Beltsville, Ma 1 ., June 8 

to June 12, 1935 



Interval from- 



Half ripe to nearly ripe 
Nearly ripe to full ripe. 
Full ripe to overripe-J. 
Half ripe to overripe— 
Nearly ripe to overripe 
Half ripe to full ripe.-. 



Blake- 
more 


Fairfax 


Dorsett 


South- 
land 


Days 


Days 


Days 


Days 


11/4 


w 


m 


w 


2K 


m 


m 


m 


2 


2H 


2H 


3^2 


5H 


m 


hYi 


6)4 


m 


m 


4 


5 


m 


2\i 


3 


2H 



Bellmar 



Days 



M 
1)4 

254 
5 
4 
2\i 



The results are generally in agreement with those obtained in North 
Carolina, the principal difference being that the period from the full- 
ripe to the overripe stage, and consequently the entire period from 
half to full ripe, was generally longer for the Maryland fruit than for 
the North Carolina fruit. This may have been due to the somewhat 
lower temperature prevailing at Beltsville during these experiments. 

On the basis of the results obtained in North Carolina and Mary- 
land it would seem advisable to pick strawberries at least every other 
day during warm weather and to take especial care that berries 
sufficiently mature for harvesting are not left in the field. This pro- 
cedure would probably also reduce the amount of decay in the field, 
and thereby help to prevent the building up of sources of infection. 



INVESTIGATIONS ON PACKING 
EFFECT OF TYPE OF CRATE 

The standard type of crate used in much of the eastern part of the 
United States has cleated dividers to separate the different layers, 
the cleats being intended to rest on the edges of the cups. The 
32-quart crate of this type is shown in figures 1, A, and 2, while a 
36-pint crate of the same type is shown in figure 1, B. This type of 
crate causes considerable damage to the fruit because the cleats on 



HANDLING AND SHIPPING STRAWBERRIES 7 

the lid and dividers crush and cut the berries which project above the 
level of the cup. It was felt, therefore, that crates that do not involve 
the use of cleated dividers might prove more desirable. Accordingly, 
a series of shipping tests was made to compare different kinds of 
crates. Figures 3 to 9 illustrate the various types of crates and cups 





-Jims 



%t 



£ 



A 



Figure 1. — A, Ordinary 32-quart crate, showing cups and dividers. Xote stains 
indicating injury from cutting and bruising of berries. B, A 36-pint crate with 
cleated dividers. The stains on the top divider indicate the extent of cutting 
and bruising injury incident to use of this type of crate. 



8 



CIRCULAR 515, U. S. DEPARTMENT OF AGRICULTURE 



used in the experiments described hereafter. Some of the shipments 
were by express, others were by truck, and some of the tests on Belts- 
ville berries were made on the jolting apparatus. The same varieties 
and the same methods of handling were used with aU the orates of a 
single series. The results are summarized in table 8. 



Mm. 
,4 






Figure 2. — Ordinary 32-quart crate partially filled with berries, showing condi- 
tion of the fruit as packed before divider is put in place and the crate is closed. 

Table 8. — Influence of type of crate on average number of strawberries per cup that 
were crushed and cut or had flattened bruises, as determined in 12 tests, A-L 







CRUSHED . 


iND 


CUT 














Type of crate 


Series 


A 


B 


c 


D 


E 


F 


G 


H 


I 


J 


K 


L 




Num- 
ber 

4.25 

.12 


Num- 
ber 
3.3 



Num- 
ber 
3.6 
.2 


Num- 
ber 
1.7 

.5 


Num- 
ber 
1.7 
.5 


Num- 
ber 
2.3 
.3 


Num- 
ber 
1.53 
.31 


Num- 
ber 
3.75 


Num- 
ber 
4.0 


Num- 
ber 
1.75 


Num- 
ber 
0.75 


Num- 
ber 
1.22 


24-quart (eared cups) _ _ 


.33 







.3 
























.25 




24-pint (eared cups) 








.1 





































FLATTENED BRUISES 



32-quart (regular). . 


5.1 
3.0 


5.0 
2.8 


3.1 
2.0 


3.2 

4.7 


1.7 
2.1 


3.9 
2.5 


2.25 
1.5 


4.75 


8.0 


4.25 


3.75 


3.44 


24-quart (eared cups) 


2-46 


1.0 


1.1 


2.5 


.6 


















1.71 




24-pint (eared cups) 


2.5 


1.7 


2.1 





































From the results shown in table 8 it is evident that all the other 
crates were a marked improvement over the regular 32-quart crate with 
regard to the average number of cut and crushed berries found per 
cup. The same held true with respect to the average number of 
berries with flattened bruises per cup, though the improvement was 



HANDLING AND SHIPPING STRAWBERRIES 



9 



less marked and less consistent. In some of the later tests it was 
found that the number of flattened bruises in the 24-quart crate with 
eared cups (fig. 9) could be reduced by increasing the height of the 
ends one-fourth of an inch. 

Obviously there would be fewer cut, crushed, or bruised strawberries 
if the 32-quart crate ordinarily used in shipment was replaced by 




Figure 3. — A, Ordinary 32-quart crate as it reaches the market, showing cutting 
and bruising of the fruit due to pressure of dividers and lid. B, Same as A, 
with cellophane-covered cups. The cellophane afforded some protection 
from foreign material but did not materially enhance the market appearance 
of the berries. 

one of the other types tested. Continued use of the 32-quart crate 
clearly nullifies much of the advantage gained by carefully grading 
the berries. 

EFFECT OF PACKING IN THE SHED 

The two common methods of packing strawberries were studied in 
test shipments from North Carolina to Washington and results are 
presented in table 9. In one method the berries were picked and 
brought to a shed to be sorted and packed, involving extra handling of 



10 



CIRCULAR 515, U. S. DEPARTMENT OF AGRICULTURE 




Figure 4. — Crate designed by the Coastal Plain Experiment Station, Willard, 
N. C, for shipment of strawberries without cutting or bruising from divider 
or lid. A sheet of cellophane is placed over each layer to keep the berries from 
falling out. 




Figure 5. — Twenty-four-quart crate of heavy veneer wood with dividers similar 
to the ordinary 32-quart crate but used with "eared" cups which support 
the dividers away from the fruit. 

the fruit ; in the other method the grading was done in the field by the 
pickers. Generally the pickers are instructed to harvest only the 
grade of berries to be shipped and to leave the small, decayed, and 
otherwise defective berries in the field. In some instances a premium 
is paid to pickers who grade and pack the berries satisfactorily. 
Sometimes the picker makes two grades. 



HANDLING AND SHIPPING STRAWBERRIES 



11 



•--- — 














Figure 6. — A wire-bound berry crate designed to prevent injury of the berries 
in shipment and to facilitate display of the fruit in all layers: A, Closed for 
shipment; B, open for display of fruit. 

It is evident from table 9 that careful picking and sorting in the 
field resulted in fruit of better shipping quality than was secured by 
rehandling and packing in the shed. The extra handling of the fruit 
involved in this latter practice markedly increased the quantity of soft, 
bruised berries. In series 3 it is evident that merely emptjung the 
fruit on the table and then replacing it in the box caused an appreciable 
increase in decayed and soft, bruised fruit. In series 5 in which the 
ordinary picked fruit showed considerable decay when picked, the 
repacked fruit from which the decayed, soft, overripe, and otherwise 



12 



CIRCULAR 515, U. S. DEPARTMENT OF AGRICULTURE 




Figure 7. — A 24-pint crate of fancy Bellmar strawberries packed for shipment in 
the crate designed by the Coastal Plain Experiment Station, Willard, N. C. 
A sheet of cellophane is placed over each layer before putting in the divider 
or nailing on the lid. 




Figure 8. — Same as figure 7 except each cup is capped with cellophane held in 

place by a rubber band. 

offgrade berries had been discarded did not have appreciably more 
sound berries upon arrival in Washington than the unsorted lot that 
was shipped just as harvested. The practice of repacking, of course, 
permits the preparation of a good-appearing pack, which doubtless 
brings a premium when sold at the shipping point. For this reason 
and others, such as the difficulty in securing very careful picking and 



HANDLING AND SHIPPING STRAWBERRIES 



13 



% 




,*•;&,. 


JtSK/^^ jBEfc 


Lstf*i % 


JMBBBBS 


■ 


I ;, 


"1 





Figure 9. — ''Eared" cups designed to reduce bruising and cutting of berries 
from pressure of dividers or lids. 

the effect of leaving overripe and decaying fruit in the field, the 
practice of repacking in the shed may have some advantages, but the 
writers are inclined to agree with Stevens and Wilcox 8 who suggest 
that when practicable, the berries should be sorted and packed as 
picked. 

Table 9. — Influence of rehandling and shed packing on the shipping quality of 
Blakemore strawberries, as compared with field packing 

[Shipped by express from Wallace, N. C, to Washington, D. C. Inspected after 2 days at air temperature] 



Series No. 



Method of handling 



Date of picking 



Sound 



Soft 
bruised 



Decayed 



1 
2 

3 

4 

5 



fCareful picking, field packing 

(.Ordinary picking, packed in shed 

fCareful picking, field packing 

(.Ordinary picking, packed in shed 

(Careful picking, field packing 

< Careful picking, packed in shed after 
I emptying on table. 

("Careful picking, field packing 

(.Ordinary picking, packed in shed 

(Careful picking, field packing 

{Ordinary picking, packed in shed 1 

[Ordinary picking, not packed 1 



Apr. 30,1935 

do 

May 2,1935 

do 

do 

do 



May 5, 1936 

do 

May 6, 1936 

do 

do 



Percent 
63.5 
48.6 
69.4 
54.4 
71.7 
52.8 

79.7 
48.1 
61.0 
43.2 
41.3 



Percent 
17.5 
19.8 
12.9 
29.6 
24.1 
37.2 

14.2 
39.7 
22.4 
40.9 
27.3 



Percent 
19.0 
31.6 
17.7 
16.0 
4.2 
10.0 

6.1 
12.2 
16.6 
15.9 
31.4 



Considerable decay was found in these lots when they were brought into the packing house. 



COMPARISON OF FACED AND JUMBLE PACKS 

The comparison of "faced" packs (arrangement of top layer of 
berries in the box in a regular manner with no stems showing) and 
"jumble" packs (merely filling the boxes, with ^ no arrangement of 
berries) on the shipping quality of strawberries is given in table 10. 
The difference found between the two types of pack is not marked. 
Generally, there was a slightly higher percentage of sound berries in 
the jumble packs. The faced packs usually had slightly less decayed 
fruit but more soft bruising. The extra handling of the fruit neces- 

8 Stevens, Neil E., and Wilcox, R. B. See footnote 5. 



14 



CIRCULAR 515, U. S. DEPARTMENT OF AGRICULTURE 



sary in making a faced pack resulted in a better appearing market 
package, and more decayed berries were discarded at the time of 
packing. On the other hand, this extra handling resulted in more 
soft bruising. In some cases also, it was noted that there was less 
slackness in the faced cups after receipt in Washington. This is 
explained by the fact that facing permits placing more berries in a 
box than when the box is not faced, even though both the faced and 
the unfaced cups are brought to the same apparent fullness. It is 
evident from table 10 that the average net weight per quart generally 
was a little higher in the faced cups. 

Table 10. — Comparison cf shipping quality of faced and jumble packs 



Shipping test 


Time be- 
tween har- 
vesting and 
inspection 


Faced or jumble 


Net 

weight 

per 

quart 


Sound 


Soft 
bruised 


Decayed 




Days 

1 

2 
2 

1 
2 
1 
2 


f Faced _ 


Grams 
598 
590 
604 
572 
570 
555 
589 
591 
595 
573 
706 
619 
653 
606 


Percent 
75.8 
74.1 
70.1 
61.1 
40.9 
48.1 
40.4 
55.8 
42.8 
42.5 
68.8 
80.7 
52.2 
59.4 


Percent 
22.9 
21.1 
14.6 
15.9 
49.8 
39.7 
51.5 
41.7 
41.2 
44.1 
25.9 
11.8 
17.7 
9.3 


Percent 
1.3 


A ___ . 












[Faced . 


15. 3 


B __. .. 












[Faced 


9.3 


C . . _ 


\Jumble " 

[Faced 






12. 2 

8. 1 


D- . 












[Faced 


16.0 


E .- . . 


\ Jumble 

[Faced 






13.4 
5.3 


F_ ________ _. 












[Faced 


30. 1 










31.3 









EFFECT OF CELLOPHANE CAPS 

Table 11. — Effect of cellophane covers for strawberry cups on quality of berries 
shipped by express from Wallace, N. C, to Washington, D. C. 





[Inspected 2 days 


after harvesting] 










Date of pick- 
ing 


Sound 


Soft bruised 


Decayed 


Variety 


Not cov- 
ered 


Covered 


Not cov- 
ered 


Covered 


Not cov- 
ered 


Covered 


Blakemore _____ 


Apr. 29,1935 
do 


Percent 
15.3 
15.2 
15.6 
36.6 
20.4 
39.5 
39.3 
28.9 
63.5 


Percent 
15.8 
12.4 
19.5 
40.5 
24.5 
26.2 
43.3 
22.9 
70.5 


Percent 
43.3 
44.6 
36.3 
40.9 
46.3 
31.6 
18.1 
44.8 
17.5 


Percent 
46.7 
47.8 
28.6 
29.8 
30.6 
43.1 
21.7 
42.8 
9.2 


Percent 
41.4 
40.2 
48.1 
22.5 
33.3 
28.9 
42.6 
26.3 
19.0 


Percent 
37.5 


Do 


39.8 




___do 


51.9 


Fairfax 

Dorsett _ _. . . 


do 

do 


29.7 
44.9 


Missionary 

Klondike 

Bellmar _ - __ 


do 

do 

do 


30.7 
35.0 
34.3 


Blakemore. 


Apr. 30,1935 


20.3 







At the time this study was made, there was considerable interest 
in North Carolina in the use of cellophane coverings for the berry 
cups, and several large shippers were using them on their fancy packs. 
Cellophane was used either as a covering for individual cups (figs. 3 
and 8) or as a sheet placed between the layers of cups (fig. 7). The 
data obtained on the influence of cellophane covers on shipping 
quality of strawberries are presented in table 11. Apparently there 



HANDLING AND SHIPPING STRAWBERRIES 



15 



was no consistent difference in shipping quality between berries with 
and without cellophane caps. Cellophane covers might aid in 
enhancing the appearance of fruit or protecting it from foreign mate- 
rial, but their use interfered with the ventilation of the berries and 
seemed to increase the humidity inside the cup, thereby favoring the 
development of mold. 

EFFECT OF TEMPERATURE ON DECAY 

The results presented in table 12 illustrate the influence of tempera- 
ture on the development of decay caused chiefly by rhizopus rot and 
gray mold rot. It will be noted that the percentage of decay inoreased 
with increasing temperatures up to 70° F., especially at those above 
40°. Rose and Gorman 9 recommend that strawberries that are to 
be shipped under refrigeration should be precooled to a temperature 
of 40° or slightly lower at the top and bottom doorway before ship- 
ment. This would mean an average fruit temperature of about 45° 
in the load. If this temperature is attained before rhizopus rot and 
gray mold rot get started the heavy losses that might otherwise develop 
can be prevented. See also Stevens. 10 

Table 12. — Influence of temperature on decay of Blakemore strawberries after 3 days' 

storage 

[Harvested June 11, 1934] 



Temper- 
ature 
(°F.) 


Sound 


Decayed ' 


Temper- 
ature 
(°F.) 


Sound 


Decayed > 


Temper- 
ature 
(°F.) 


Sound 


Decayed 1 


80 

70 

60 


Percent 
19.5 
20.8 
55.4 


Percent 
80.5 
79.2 
44.6 


50 

40 


Percent 
78.5 
90.0 


Percent 
21.5 
10.0 


36 

32 


Percent 
92.6 
94.8 


Percent 
7.4 
5.2 



i Chiefly rhizopus rot and gray mold rot. 

In order to keep decay at a minimum in nonrefrigerated shipments 
it is necessary to shorten as much as possible the time that straw- 
berries are held at high temperatures. 

SUMMARY 

Picking strawberries early in the morning while the fruit and air 
temperatures were relatively cool resulted in better shipping quality 
than picking later in the day. 

Care in picking is an extremely important factor in the carrying 
quality of strawberries. 

Berries harvested when fully ripe were of very poor shipping quality 
in comparison with those picked somewhat less mature. 

Studies on the rate of ripening of strawberries in the field indicate 
the advisability of picking clean at least every other day, especially 
during warm weather. 

It seems advisable to replace the standard 32-quart crate now in 
use with one designed to cause less crushing and cutting of the fruit. 

9 Rose, D. H., and Gorman, E. A., Jr. See footnote 2. 

io Stevexs, Neil E. strawberry diseases. U. S. Dept. Agr. Farmers' Bull. 1458, 10 pp., illus. 1925. 
(Revised, 1933.) 



16 CIRCULAR 515, U. S. DEPARTMENT OF AGRICULTURE 

Training the pickers to pick carefully so as to eliminate the neces- 
sity of repacking is advisable from the standpoint of shipping quality, 
if it can be accomplished. Frequent picking to lessen decay in the 
field and cultural treatments to reduce the number of small berries 
that should be graded out would be helpful in this respect. 

The difference in carrying quality between "faced" and "jumble" 
packs was not marked. Facing results in a better appearing pack on 
the market. 

In these tests there was no consistent difference in shipping quality 
between berries covered with cellophane and those not so covered. 

Decay of strawberries was closely associated with temperature,, 
especially above 40° F. 



U. S. GOVERNMENT PRINTING OFFICE: 1939 



For sale by the Superintendent of Documents, Washington, D. C. - - - P.rice 5 cents